In order to curb the problem of ink running on printable DVDs if water gets on them, someone suggested using fixative spray. But I can only find ones specifically for DVDs/CDs in the UK, know of anywhere in the US I can buy? Ghiant and Pressit are brands I've seen in England....
Patricia Nomick's. You can find it in the Arts & Crafts section at Wal-Mart... About $5/can, and it contains the exact same ingredients as the two you mentioned...
I use KRYLON Low Odour Clear Gloss. Works great and gives the CD/DVD's a nice almost factory printed look. It does not smell much and can be used indoors.
I got mine at a CanadianTire store, but i am guessing most hardware/ paint stores will carry it, and perhaps even some arts and crafts stores.